This an idea I had a few years back, completely forgot about it. It's a stock graphic equalizer for the factory stereo. The factory stereo has been upgraded to aftermarket. It can be made to work with the aftermarket stereo but it will only ruin the sound and/or display nothing due to being out of range.
So I had this idea of re-purposing it to show engine parameters. I get a signal from a oil pressure sender send that to an Arduino which produces a tone signal which goes to the input of the EQ within a certain range. Then do the same with engine temp, rpm, maybe a boost gauge. There's adjustability to the EQ in each band, I'm not expecting to make a precision device that I will rely on, just something neat.
So the question is can an Arduino handle making multiple tones like that based on separate analog inputs? Multiple Arduinos? Or another device completely?